Aircraft Sizing

Preliminary Sizing

Accurate sizing at the conceptual stage is critical to ensuring that future design decisions remain feasible, efficient, and aligned with program goals. At Fabexco, we perform detailed preliminary sizing studies based on mission requirements, physical principles of flight, and applicable certification constraints – producing data that informs configuration selection, tradespace analysis, and downstream subsystem development.

Our work lays the foundation for design convergence by identifying key vehicle-level parameters and bounding the performance space early in the lifecycle – reducing risk and iteration later in development.

Our analysis includes:

• Required Thrust/Power: Estimating propulsion needs based on performance requirements and applicable regulations
• Wing Planform Sizing: Defining the optimal span, area, aspect ratio, and sweep for aerodynamic efficiency and integration
• Empennage Geometry: Establishing required tail volume coefficients, placement, and effectiveness
• Gross Weight Breakdown: Estimating component group weights, fuel fractions, and structural allocation
• Takeoff & Landing Performance Sizing: Meeting regulatory field length limits and safety margins
• Preliminary Aerodynamic Estimates: Empirically estimating lift, and drag polars
• Constraint Diagram Generation: Plotting thrust-to-weight vs. wing loading constraint curves for mission and regulatory compliance
• Sensitivity and Margin Analysis: Identifying high-leverage design variables based on mission definition and flight physics

Typical deliverables include:

• A structured database of all primary design variables, geometry parameters, and weight estimates
• Clear documentation of the sizing process, including equations, assumptions, and traceable calculations
• Performance plots (e.g. constraint diagrams, payload-range charts) visualizing design margins and tradeoffs
• Optional CAD-ready geometric profiles based on initial planform and volume estimates

This early analysis ensures that every major design decision – from propulsion integration to airframe layout – is grounded in physics, aligned with program objectives, and ready for refinement in detailed design.